-> BlockAnd<()> {
let discriminant_place = unpack!(block = self.as_place(block, discriminant));
+ // Matching on a `discriminant_place` with an uninhabited type doesn't
+ // generate any memory reads by itself, and so if the place "expression"
+ // contains unsafe operations like raw pointer dereferences or union
+ // field projections, we wouldn't know to require an `unsafe` block
+ // around a `match` equivalent to `std::intrinsics::unreachable()`.
+ // See issue #47412 for this hole being discovered in the wild.
+ //
+ // HACK(eddyb) Work around the above issue by adding a dummy inspection
+ // of `discriminant_place`, specifically by applying `Rvalue::Discriminant`
+ // (which will work regardless of type) and storing the result in a temp.
+ let dummy_source_info = self.source_info(span);
+ let dummy_access = Rvalue::Discriminant(discriminant_place.clone());
+ let dummy_ty = dummy_access.ty(&self.local_decls, self.hir.tcx());
+ let dummy_temp = self.temp(dummy_ty, dummy_source_info.span);
+ self.cfg.push_assign(block, dummy_source_info, &dummy_temp, dummy_access);
+
let mut arm_blocks = ArmBlocks {
blocks: arms.iter()
.map(|_| self.cfg.start_new_block())
{
let mut e = Baz::X(2);
let _e0 = e.x();
- match e {
+ match e { //[mir]~ ERROR cannot use `e` because it was mutably borrowed
Baz::X(value) => value
//[ast]~^ ERROR cannot use `e.0` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `e.0` because it was mutably borrowed
{
let mut e = Box::new(Baz::X(3));
let _e0 = e.x();
- match *e {
+ match *e { //[mir]~ ERROR cannot use `*e` because it was mutably borrowed
Baz::X(value) => value
//[ast]~^ ERROR cannot use `e.0` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `e.0` because it was mutably borrowed
{
let mut v = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let _v = &mut v;
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[x, _, .., _, _] => println!("{}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, x, .., _, _] => println!("{}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, _, .., x, _] => println!("{}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, _, .., _, x] => println!("{}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
{
let mut v = &[1, 2, 3, 4, 5];
let _v = &mut v;
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[x..] => println!("{:?}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, x..] => println!("{:?}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[x.., _] => println!("{:?}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
_ => panic!("other case"),
}
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, x.., _] => println!("{:?}", x),
//[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
//[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
let mut e = E::A(3);
let _e = &mut e;
- match e {
+ match e { //[mir]~ ERROR cannot use `e` because it was mutably borrowed
E::A(ref ax) =>
//[ast]~^ ERROR cannot borrow `e.0` as immutable because `e` is also borrowed as mutable
//[mir]~^^ ERROR cannot borrow `e.0` as immutable because it is also borrowed as mutable
struct S { x: F, y: (u32, u32), };
let mut s = S { x: F { x: 1, y: 2}, y: (999, 998) };
let _s = &mut s;
- match s {
+ match s { //[mir]~ ERROR cannot use `s` because it was mutably borrowed
S { y: (ref y0, _), .. } =>
//[ast]~^ ERROR cannot borrow `s.y.0` as immutable because `s` is also borrowed as mutable
//[mir]~^^ ERROR cannot borrow `s.y.0` as immutable because it is also borrowed as mutable
println!("y0: {:?}", y0),
_ => panic!("other case"),
}
- match s {
+ match s { //[mir]~ ERROR cannot use `s` because it was mutably borrowed
S { x: F { y: ref x0, .. }, .. } =>
//[ast]~^ ERROR cannot borrow `s.x.y` as immutable because `s` is also borrowed as mutable
//[mir]~^^ ERROR cannot borrow `s.x.y` as immutable because it is also borrowed as mutable
struct F {x: u32, y: u32};
let mut v = &[F{x: 1, y: 2}, F{x: 3, y: 4}];
let _v = &mut v;
- match v {
+ match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
&[_, F {x: ref xf, ..}] => println!("{}", xf),
//[mir]~^ ERROR cannot borrow `v[..].x` as immutable because it is also borrowed as mutable
// No errors in AST
fn match_enum() {
let mut foo = Foo::B;
let p = &mut foo;
- let _ = match foo {
+ let _ = match foo { //[mir]~ ERROR [E0503]
Foo::B => 1, //[mir]~ ERROR [E0503]
_ => 2,
Foo::A(x) => x //[ast]~ ERROR [E0503]
fn main() {
let mut x = 1;
let _x = &mut x;
- let _ = match x {
+ let _ = match x { //[mir]~ ERROR [E0503]
x => x + 1, //[ast]~ ERROR [E0503]
//[mir]~^ ERROR [E0503]
y => y + 2, //[ast]~ ERROR [E0503]
--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[derive(Copy, Clone)]
+enum Void {}
+
+// Tests that we detect unsafe places (specifically, union fields and
+// raw pointer dereferences), even when they're matched on while having
+// an uninhabited type (equivalent to `std::intrinsics::unreachable()`).
+
+fn union_field() {
+ union Union { unit: (), void: Void }
+ let u = Union { unit: () };
+ match u.void {}
+ //~^ ERROR access to union field requires unsafe function or block
+}
+
+fn raw_ptr_deref() {
+ let ptr = std::ptr::null::<Void>();
+ match *ptr {}
+ //~^ ERROR dereference of raw pointer requires unsafe function or block
+}
+
+fn main() {}
// bb0: {
// ...
// _2 = std::option::Option<i32>::Some(const 42i32,);
-// _5 = discriminant(_2);
-// switchInt(move _5) -> [0isize: bb6, 1isize: bb4, otherwise: bb8];
+// _3 = discriminant(_2);
+// _6 = discriminant(_2);
+// switchInt(move _6) -> [0isize: bb6, 1isize: bb4, otherwise: bb8];
// }
// bb1: {
// resume;
// }
// bb2: { // arm1
-// StorageLive(_7);
-// _7 = _3;
-// _1 = (const 1i32, move _7);
-// StorageDead(_7);
+// StorageLive(_8);
+// _8 = _4;
+// _1 = (const 1i32, move _8);
+// StorageDead(_8);
// goto -> bb13;
// }
// bb3: { // binding3(empty) and arm3
// unreachable;
// }
// bb9: { // binding1 and guard
-// StorageLive(_3);
-// _3 = ((_2 as Some).0: i32);
-// StorageLive(_6);
-// _6 = const guard() -> [return: bb10, unwind: bb1];
+// StorageLive(_4);
+// _4 = ((_2 as Some).0: i32);
+// StorageLive(_7);
+// _7 = const guard() -> [return: bb10, unwind: bb1];
// }
// bb10: { // end of guard
-// switchInt(move _6) -> [0u8: bb11, otherwise: bb2];
+// switchInt(move _7) -> [0u8: bb11, otherwise: bb2];
// }
// bb11: { // to pre_binding2
// falseEdges -> [real: bb5, imaginary: bb5];
// }
// bb12: { // bindingNoLandingPads.before.mir2 and arm2
-// StorageLive(_4);
-// _4 = ((_2 as Some).0: i32);
-// StorageLive(_8);
-// _8 = _4;
-// _1 = (const 2i32, move _8);
-// StorageDead(_8);
+// StorageLive(_5);
+// _5 = ((_2 as Some).0: i32);
+// StorageLive(_9);
+// _9 = _5;
+// _1 = (const 2i32, move _9);
+// StorageDead(_9);
// goto -> bb13;
// }
// bb13: {
// bb0: {
// ...
// _2 = std::option::Option<i32>::Some(const 42i32,);
-// _5 = discriminant(_2);
-// switchInt(move _5) -> [0isize: bb5, 1isize: bb4, otherwise: bb8];
+// _3 = discriminant(_2);
+// _6 = discriminant(_2);
+// switchInt(move _6) -> [0isize: bb5, 1isize: bb4, otherwise: bb8];
// }
// bb1: {
// resume;
// }
// bb2: { // arm1
-// StorageLive(_7);
-// _7 = _3;
-// _1 = (const 1i32, move _7);
-// StorageDead(_7);
+// StorageLive(_8);
+// _8 = _4;
+// _1 = (const 1i32, move _8);
+// StorageDead(_8);
// goto -> bb13;
// }
// bb3: { // binding3(empty) and arm3
// unreachable;
// }
// bb9: { // binding1 and guard
-// StorageLive(_3);
-// _3 = ((_2 as Some).0: i32);
-// StorageLive(_6);
-// _6 = const guard() -> [return: bb10, unwind: bb1];
+// StorageLive(_4);
+// _4 = ((_2 as Some).0: i32);
+// StorageLive(_7);
+// _7 = const guard() -> [return: bb10, unwind: bb1];
// }
// bb10: { // end of guard
-// switchInt(move _6) -> [0u8: bb11, otherwise: bb2];
+// switchInt(move _7) -> [0u8: bb11, otherwise: bb2];
// }
// bb11: { // to pre_binding2
// falseEdges -> [real: bb6, imaginary: bb5];
// }
// bb12: { // binding2 and arm2
-// StorageLive(_4);
-// _4 = ((_2 as Some).0: i32);
-// StorageLive(_8);
-// _8 = _4;
-// _1 = (const 2i32, move _8);
-// StorageDead(_8);
+// StorageLive(_5);
+// _5 = ((_2 as Some).0: i32);
+// StorageLive(_9);
+// _9 = _5;
+// _1 = (const 2i32, move _9);
+// StorageDead(_9);
// goto -> bb13;
// }
// bb13: {
// bb0: {
// ...
// _2 = std::option::Option<i32>::Some(const 1i32,);
-// _7 = discriminant(_2);
-// switchInt(move _7) -> [1isize: bb4, otherwise: bb5];
+// _3 = discriminant(_2);
+// _8 = discriminant(_2);
+// switchInt(move _8) -> [1isize: bb4, otherwise: bb5];
// }
// bb1: {
// resume;
// unreachable;
// }
// bb9: { // binding1: Some(w) if guard()
-// StorageLive(_3);
-// _3 = ((_2 as Some).0: i32);
-// StorageLive(_8);
-// _8 = const guard() -> [return: bb10, unwind: bb1];
+// StorageLive(_4);
+// _4 = ((_2 as Some).0: i32);
+// StorageLive(_9);
+// _9 = const guard() -> [return: bb10, unwind: bb1];
// }
// bb10: { //end of guard
-// switchInt(move _8) -> [0u8: bb11, otherwise: bb2];
+// switchInt(move _9) -> [0u8: bb11, otherwise: bb2];
// }
// bb11: { // to pre_binding2
// falseEdges -> [real: bb5, imaginary: bb5];
// }
// bb12: { // binding2 & arm2
-// StorageLive(_4);
-// _4 = _2;
+// StorageLive(_5);
+// _5 = _2;
// _1 = const 2i32;
// goto -> bb17;
// }
// bb13: { // binding3: Some(y) if guard2(y)
-// StorageLive(_5);
-// _5 = ((_2 as Some).0: i32);
-// StorageLive(_10);
+// StorageLive(_6);
+// _6 = ((_2 as Some).0: i32);
// StorageLive(_11);
-// _11 = _5;
-// _10 = const guard2(move _11) -> [return: bb14, unwind: bb1];
+// StorageLive(_12);
+// _12 = _6;
+// _11 = const guard2(move _12) -> [return: bb14, unwind: bb1];
// }
// bb14: { // end of guard2
-// StorageDead(_11);
-// switchInt(move _10) -> [0u8: bb15, otherwise: bb3];
+// StorageDead(_12);
+// switchInt(move _11) -> [0u8: bb15, otherwise: bb3];
// }
// bb15: { // to pre_binding4
// falseEdges -> [real: bb7, imaginary: bb7];
// }
// bb16: { // binding4 & arm4
-// StorageLive(_6);
-// _6 = _2;
+// StorageLive(_7);
+// _7 = _2;
// _1 = const 4i32;
// goto -> bb17;
// }
//~^ ERROR use of partially moved value: `maybe` (Ast) [E0382]
//~| ERROR use of moved value: `(maybe as std::prelude::v1::Some).0` (Ast) [E0382]
//~| ERROR use of moved value: `maybe` (Mir) [E0382]
+ //~| ERROR use of moved value: `maybe` (Mir) [E0382]
//~| ERROR use of moved value: `maybe.0` (Mir) [E0382]
}
}
|
= note: move occurs because the value has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
+error[E0382]: use of moved value: `maybe` (Mir)
+ --> $DIR/issue-41962.rs:17:9
+ |
+17 | if let Some(thing) = maybe {
+ | ^ ----- value moved here
+ | _________|
+ | |
+18 | | //~^ ERROR use of partially moved value: `maybe` (Ast) [E0382]
+19 | | //~| ERROR use of moved value: `(maybe as std::prelude::v1::Some).0` (Ast) [E0382]
+20 | | //~| ERROR use of moved value: `maybe` (Mir) [E0382]
+21 | | //~| ERROR use of moved value: `maybe` (Mir) [E0382]
+22 | | //~| ERROR use of moved value: `maybe.0` (Mir) [E0382]
+23 | | }
+ | |_________^ value used here after move
+ |
+ = note: move occurs because `maybe` has type `std::option::Option<std::vec::Vec<bool>>`, which does not implement the `Copy` trait
+
error[E0382]: use of moved value: `maybe` (Mir)
--> $DIR/issue-41962.rs:17:16
|
|
= note: move occurs because `maybe.0` has type `std::vec::Vec<bool>`, which does not implement the `Copy` trait
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
let mut e = Xyz::A;
let f = &mut e;
let g = f;
- match e {
+ match e { //~ cannot use `e` because it was mutably borrowed [E0503]
Xyz::A => println!("a"),
//~^ cannot use `e` because it was mutably borrowed [E0503]
Xyz::B => println!("b"),
+error[E0503]: cannot use `e` because it was mutably borrowed
+ --> $DIR/borrowed-match-issue-45045.rs:24:5
+ |
+22 | let f = &mut e;
+ | ------ borrow of `e` occurs here
+23 | let g = f;
+24 | / match e { //~ cannot use `e` because it was mutably borrowed [E0503]
+25 | | Xyz::A => println!("a"),
+26 | | //~^ cannot use `e` because it was mutably borrowed [E0503]
+27 | | Xyz::B => println!("b"),
+28 | | };
+ | |_____^ use of borrowed `e`
+
error[E0503]: cannot use `e` because it was mutably borrowed
--> $DIR/borrowed-match-issue-45045.rs:25:9
|
25 | Xyz::A => println!("a"),
| ^^^^^^ use of borrowed `e`
-error: aborting due to previous error
+error: aborting due to 2 previous errors
projects / rust.git / commitdiff